dendrite/internal/caching/impl_inmemorylru.go
2020-06-12 11:07:26 +01:00

81 lines
1.8 KiB
Go

package caching
import (
"fmt"
lru "github.com/hashicorp/golang-lru"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
func NewInMemoryLRUCache() (*Caches, error) {
roomVersions, err := NewInMemoryLRUCachePartition(
RoomVersionCacheName,
RoomVersionCacheMutable,
RoomVersionCacheMaxEntries,
)
if err != nil {
return nil, err
}
serverKeys, err := NewInMemoryLRUCachePartition(
ServerKeyCacheName,
ServerKeyCacheMutable,
ServerKeyCacheMaxEntries,
)
if err != nil {
return nil, err
}
return &Caches{
RoomVersions: roomVersions,
ServerKeys: serverKeys,
}, nil
}
type InMemoryLRUCachePartition struct {
name string
mutable bool
maxEntries int
lru *lru.Cache
}
func NewInMemoryLRUCachePartition(name string, mutable bool, maxEntries int) (*InMemoryLRUCachePartition, error) {
var err error
cache := InMemoryLRUCachePartition{
name: name,
mutable: mutable,
maxEntries: maxEntries,
}
cache.lru, err = lru.New(maxEntries)
if err != nil {
return nil, err
}
promauto.NewGaugeFunc(prometheus.GaugeOpts{
Namespace: "dendrite",
Subsystem: "caching_in_memory_lru",
Name: name,
}, func() float64 {
return float64(cache.lru.Len())
})
return &cache, nil
}
func (c *InMemoryLRUCachePartition) Set(key string, value interface{}) {
if !c.mutable {
if peek, ok := c.lru.Peek(key); ok && peek != value {
panic(fmt.Sprintf("invalid use of immutable cache tries to mutate existing value of %q", key))
}
}
c.lru.Add(key, value)
}
func (c *InMemoryLRUCachePartition) Unset(key string) {
if !c.mutable {
panic(fmt.Sprintf("invalid use of immutable cache tries to unset value of %q", key))
}
c.lru.Remove(key)
}
func (c *InMemoryLRUCachePartition) Get(key string) (value interface{}, ok bool) {
return c.lru.Get(key)
}